2017-12-17 00:11:13

by Prakhya, Sai Praneeth

[permalink] [raw]
Subject: [PATCH 1/3] efi: Use efi_mm in x86 as well as ARM

From: Sai Praneeth <[email protected]>

Presently, only ARM uses mm_struct to manage efi page tables and efi
runtime region mappings. As this is the preferred approach, let's make
this data structure common across architectures. Specially, for x86,
using this data structure improves code maintainability and readability.

Signed-off-by: Sai Praneeth Prakhya <[email protected]>
Cc: Lee, Chun-Yi <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Ricardo Neri <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Ravi Shankar <[email protected]>
Tested-by: Bhupesh Sharma <[email protected]>
---
arch/x86/include/asm/efi.h | 4 ++++
arch/x86/platform/efi/efi_64.c | 3 +++
drivers/firmware/efi/arm-runtime.c | 9 ---------
drivers/firmware/efi/efi.c | 9 +++++++++
include/linux/efi.h | 2 ++
5 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 85f6ccb80b91..00f977ddd718 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -2,10 +2,14 @@
#ifndef _ASM_X86_EFI_H
#define _ASM_X86_EFI_H

+#include <linux/sched/mm.h>
+#include <linux/sched/task.h>
+
#include <asm/fpu/api.h>
#include <asm/pgtable.h>
#include <asm/processor-flags.h>
#include <asm/tlb.h>
+#include <asm/mmu_context.h>

/*
* We map the EFI regions needed for runtime services non-contiguously,
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 6a151ce70e86..ccf5239923e8 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -227,6 +227,9 @@ int __init efi_alloc_page_tables(void)
return -ENOMEM;
}

+ mm_init_cpumask(&efi_mm);
+ init_new_context(NULL, &efi_mm);
+
return 0;
}

diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index 1cc41c3d6315..d6b26534812b 100644
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -31,15 +31,6 @@

extern u64 efi_system_table;

-static struct mm_struct efi_mm = {
- .mm_rb = RB_ROOT,
- .mm_users = ATOMIC_INIT(2),
- .mm_count = ATOMIC_INIT(1),
- .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
- .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
- .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
-};
-
#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
#include <asm/ptdump.h>

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 557a47829d03..760260b933b6 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -74,6 +74,15 @@ static unsigned long *efi_tables[] = {
&efi.mem_attr_table,
};

+struct mm_struct efi_mm = {
+ .mm_rb = RB_ROOT,
+ .mm_users = ATOMIC_INIT(2),
+ .mm_count = ATOMIC_INIT(1),
+ .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
+ .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
+ .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
+};
+
static bool disable_runtime;
static int __init setup_noefi(char *arg)
{
diff --git a/include/linux/efi.h b/include/linux/efi.h
index d813f7b04da7..6745f4dbbcc1 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -928,6 +928,8 @@ extern struct efi {
unsigned long flags;
} efi;

+extern struct mm_struct efi_mm;
+
static inline int
efi_guidcmp (efi_guid_t left, efi_guid_t right)
{
--
2.1.4